1. The problem statement, all variables and given/known data Given an AC Voltage that varies in time according to the equation: v(t) = 100 sin(250t) (i) What is the frequency of this waveform? (ii) Calculate the time for one complete cycle of the voltage? (iii) Calculate the instantaneous value of the voltage at time = 6ms. (iv) Calculate the Root-Mean Square (RMS) value of the AC voltage. (v) The first time after t=0ms that the instantaneous voltage is 50V. 2. Relevant equations v(t) sin (250 x 6 x 10^-3) 3. The attempt at a solution I'm trying to, obviously, get the third part of this. What I have so far is: 100sin (250pi x 6 x 10^-3) =100sin (4.71) In an example in my book it then goes on to multiply 100 x .951... where does the .951 come from and is this what I use for this equation or should I use a different number? The equation in the book I have is (still 6ms): v(t) = 100sin (100pi t) V Their solution is: 100 sin (100pi x 6 x 10^-3) =100sin (1.88) =100 x .951 =95.1V Not sure what I'm missing?